The present invention relates to a personal computer which displays display data inputted from another personal computer.
Recently, in order to differently use the fixed personal computer and the portable personal computer in accordance with their needs, there is a tendency that users increase who possess two computers including a desktop computer and a notebook computer.
Here, as compared with a Liquid Crystal Display (LCD) of the desktop computer, an LCD of the notebook computer is smaller and has a lower brightness. Therefore, it is a convenience that the LCD of the desktop computer can be used as a display of the notebook computer.
Then, there is a conventional desktop computer, which displays display data inputted from a notebook computer as an analog RGB (Red, Green and Blue) signal via a cable. In this conventional desktop computer, it is necessary to convert the analog RGB signal inputted from the notebook computer into a digital RGB signal. Accordingly, the conventional desktop computer is completely switched on, although there are portions, which do not need to be supplied with electric power, for example, a CPU (a Central Processing Unit), a HDD (a Hard Disc Drive) and a memory. Namely, there is a problem that saving power cannot be accomplished in the conventional desktop computer.
An object of the present invention is to provide a personal computer which displays display data inputted from another personal computer, while the saving of the electric power is accomplished.
According to the present invention, a personal computer includes: a display controller which outputs a first RGB signal; a first control circuit to which electric power is supplied at all times, receiving the first RGB signal and a second RGB signal from another personal computer and outputs the first RGB signal or the second RGB signal; an LCD unit which receives the first RGB signal or the second RGB signal; a second control circuit to which electric power is supplied at all times, detecting that the second RGB signal is inputted to the first control circuit; and a power supply circuit. The second control circuit controls the first control circuit to output the second RGB signal to the LCD unit and controls the power supply circuit to supply electric power to the LCD unit, when the second control circuit detects that the second RGB signal is inputted to the first control circuit.